This invention relates to an oil spill cleanup and recovery method and articles for use in said method.
Accidental oil spills have become a very costly occurrence, and a serious environmental danger.
Various inorganic, natural organic, and synthetic materials have been tried for controlling these oil spills. Some of these materials must be disposed of by burning or other means after cleanup. Others, such as detergents and emulsifying agents work by dispersing the oil in solution with the body of water. A third group, for example polymeric foams and liquids, absorb the oil. Among the polymeric foams, the generally recognized best type previously suggested has been polyurethane.
Various prior art systems which have been suggested suffer from one or more problems, complications, and disadvantages.
Yahnke, U.S. Pat. No. 3,578,585, showed a rotating cylinder having a porous outer layer made of polyurethane to absorb oil and a roller means to apply pressure to squeeze the oil.
According to Johnston, U.S. Pat. No. 3,617,551, a flow through chamber containing a polyurethane foam cartridge can be used. Johnston's device also involves a piston-like member to squeeze the foam to recover the absorbed oil.
In Miranda, U.S. Pat. No. 3,886,067, oil sliks are controlled by spraying reactive polyurethane resin-forming materials from a plane or boat onto the spill. The polyurethane foam particles react with and bind the oil to form foam particles. No method of recovery of the foam particles and the entrapped oil is disclosed.
According to Buckley et al., U.S. Pat. No. 3,539,508, a pair of spaced, revolving pickup members dip into the liquid oil spill. One of the cylinders has a polyurethane foam surface, whereas the other has a smooth polyethylene surfaces.
According to De Young, U.S. Pat. No. 3,888,766, oil spills are removed by using a cellular material impregnated with a hydrophobic and oleophilic sealant. Specific cellular materials mentioned by De Young are asbestos, perlite powder, talc, volcanic ash, vermiculite, ground corn cob, wood fiber, fiberboard, hay, sawdust, straw, open cell polyurethane, urea formaldehyde, polyethylene, polypropylene, and polystyrene. Also, cellulose fiber-perlite mixtures, plastic shavings, refuse compost, and mixtures of synthetic fibers.
The polyurethane foams used for oil spill cleanup in the prior art are, according to the references, open celled.
To date, none of the prior oil absorbing systems is completely satisfactory because of certain problems. Polyurethane foam is not hydrophobic enough to avoid picking up undue amounts of water along with the oil when used to control oil spills. Furthermore, storage of polyurethane foam can be dangerous and hazardous to its flamability. Also, the general methods of use of the foams previously suggested are either too complex and, hence, expensive and cumbersome in use, or are ineffective and labor intensive.